1. Field of the Invention
Embodiments of the invention generally relate to processing pad conditioning apparatus.
2. Description of the Related Art
Chemical Mechanical Polishing (CMP) is a technique used to remove materials from a substrate surface in part by chemical dissolution while concurrently polishing the substrate. Chemical dissolution is performed by applying a reactive chemical slurry to a substrate surface to remove conductive materials from the substrate surface. The slurry may be applied to the substrate surface by contact with a polishing material upon which the substrate is processed. In one embodiment, the polishing material may be a polishing pad disposed on a platen. A mechanical component of the polishing process is performed by providing relative motion between the substrate and the polishing material. The mechanical component of the process enhances the rate at which the conductive material is removed from the substrate.
Over time, the effectiveness of the polishing pad diminishes as pressure, friction, and heat combine with particulate matter from processing slurries, materials removed from the substrate (or from the pad itself), and the like, to form a hard, relatively smooth surface on the pad. This effect is typically called “glazing.”
In order to improve the effectiveness of the polishing pad after glazing has occurred, the polishing pad may be periodically conditioned. One conventional pad conditioner, described in U.S. Pat. No. 5,081,051, entitled, “Method For Conditioning The Surface Of A Polishing Pad,” utilizes a rigid, serrated blade to roughen the surface of the polishing pad. Another conventional pad conditioner, described in U.S. Pat. Nos. 5,785,585 and 6,273,797, respectively entitled, “Polish Pad Conditioner With Radial Compensation,” and “In-situ Automated CMP Wedge Conditioner,” utilizes a serrated wedge loosely contained in a holder. Although the pad conditioners described in these patents allow for some movement of the conditioning elements, the serrated blade and serrated wedge themselves are rigid and inflexible. This inflexibility hampers the ability of the conditioner to provide local control over the polishing profile.
Therefore, there is a need for an improved polishing pad conditioner with improved flexibility and control over the local polishing profile of the polishing pad.